Trial Outcomes & Findings for Apalutamide With or Without Stereotactic Body Radiation in Treating Castration-Resistant Prostate Cancer (NCT NCT03503344)
NCT ID: NCT03503344
Last Updated: 2026-01-21
Results Overview
The primary endpoint for the study is the proportion of participants with undetectable serum PSA (\< 0.2 ng/mL) at 6 months following completion of apalutamide therapy (18 months from date of randomization). Participants who discontinue apalutamide prior to completion of 12 months of therapy for reasons other than disease progression by Prostate Cancer Clinical Trials Working Group (PCWG) criteria, as well as participants who withdraw or are lost to follow up, will be considered unevaluable for this analysis. Participants who discontinue treatment for radiographic or clinical progression, even if occurring prior to receipt of Stereotactic radiation therapy (SBRT) in the experimental arm), would be evaluable for analysis of the primary endpoint.
Recruitment status
COMPLETED
Study phase
PHASE2
Target enrollment
26 participants
Primary outcome timeframe
Approximately 18 months from date of randomization
Results posted on
2026-01-21
Participant Flow
Participant milestones
| Measure |
Arm A (Apalutamide Montherapy)
Participants receive apalutamide PO QD on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity.
|
Arm B (Apalutamide, SBRT)
Participants receive apalutamide orally (PO) once a day (QD) on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Beginning 60 days after first dose of apalutamide, participants also undergo stereotactic body radiation therapy for 1-5 fractions.
|
|---|---|---|
|
Overall Study
STARTED
|
13
|
13
|
|
Overall Study
COMPLETED
|
13
|
13
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Apalutamide With or Without Stereotactic Body Radiation in Treating Castration-Resistant Prostate Cancer
Baseline characteristics by cohort
| Measure |
Arm A (Apalutamide Monotherapy)
n=13 Participants
Participants receive apalutamide PO QD on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity.
|
Arm B (Apalutamide, SBRT)
n=13 Participants
Participants receive apalutamide orally (PO) once a day (QD) on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Beginning 60 days after first dose of apalutamide, participants also undergo stereotactic body radiation therapy for 1-5 fractions.
|
Total
n=26 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Customized
50-59 years old
|
0 Participants
n=37 Participants
|
1 Participants
n=44 Participants
|
1 Participants
n=40 Participants
|
|
Age, Customized
60-69 years old
|
2 Participants
n=37 Participants
|
3 Participants
n=44 Participants
|
5 Participants
n=40 Participants
|
|
Age, Customized
70-79 years old
|
9 Participants
n=37 Participants
|
8 Participants
n=44 Participants
|
17 Participants
n=40 Participants
|
|
Age, Customized
80-89 years old
|
2 Participants
n=37 Participants
|
1 Participants
n=44 Participants
|
3 Participants
n=40 Participants
|
|
Sex: Female, Male
Female
|
0 Participants
n=37 Participants
|
0 Participants
n=44 Participants
|
0 Participants
n=40 Participants
|
|
Sex: Female, Male
Male
|
13 Participants
n=37 Participants
|
13 Participants
n=44 Participants
|
26 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
0 Participants
n=37 Participants
|
1 Participants
n=44 Participants
|
1 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
13 Participants
n=37 Participants
|
12 Participants
n=44 Participants
|
25 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=37 Participants
|
0 Participants
n=44 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=37 Participants
|
0 Participants
n=44 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Asian
|
1 Participants
n=37 Participants
|
0 Participants
n=44 Participants
|
1 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=37 Participants
|
0 Participants
n=44 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=37 Participants
|
0 Participants
n=44 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
White
|
12 Participants
n=37 Participants
|
11 Participants
n=44 Participants
|
23 Participants
n=40 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=37 Participants
|
2 Participants
n=44 Participants
|
2 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=37 Participants
|
0 Participants
n=44 Participants
|
0 Participants
n=40 Participants
|
|
Region of Enrollment
United States
|
13 Participants
n=37 Participants
|
13 Participants
n=44 Participants
|
26 Participants
n=40 Participants
|
PRIMARY outcome
Timeframe: Approximately 18 months from date of randomizationThe primary endpoint for the study is the proportion of participants with undetectable serum PSA (\< 0.2 ng/mL) at 6 months following completion of apalutamide therapy (18 months from date of randomization). Participants who discontinue apalutamide prior to completion of 12 months of therapy for reasons other than disease progression by Prostate Cancer Clinical Trials Working Group (PCWG) criteria, as well as participants who withdraw or are lost to follow up, will be considered unevaluable for this analysis. Participants who discontinue treatment for radiographic or clinical progression, even if occurring prior to receipt of Stereotactic radiation therapy (SBRT) in the experimental arm), would be evaluable for analysis of the primary endpoint.
Outcome measures
| Measure |
Arm A (Apalutamide Monotherapy)
n=13 Participants
Participants receive apalutamide PO QD on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity.
|
Arm B (Apalutamide, SBRT)
n=13 Participants
Participants receive apalutamide orally (PO) once a day (QD) on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Beginning 60 days after first dose of apalutamide, participants also undergo stereotactic body radiation therapy for 1-5 fractions.
|
|---|---|---|
|
Proportion of Participants With Undetectable Serum Prostate-specific Antigen (PSA)
|
0 proportion of participants
|
0.308 proportion of participants
|
SECONDARY outcome
Timeframe: Up to 36 monthsTime to a diagnosis of PSA progression defined by the Prostate Cancer Working Group (PCWG) criteria will be estimated using Kaplan-Meier methods for each treatment arm and will be used to estimate the median time to progression and 95% confidence interval (CI).
Outcome measures
| Measure |
Arm A (Apalutamide Monotherapy)
n=13 Participants
Participants receive apalutamide PO QD on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity.
|
Arm B (Apalutamide, SBRT)
n=13 Participants
Participants receive apalutamide orally (PO) once a day (QD) on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Beginning 60 days after first dose of apalutamide, participants also undergo stereotactic body radiation therapy for 1-5 fractions.
|
|---|---|---|
|
Median Time to PSA Progression
|
13.82 months
Interval 9.21 to
There were insufficient number of events so an upper limit to for the confidence interval could not be calculated.
|
NA months
Interval 30.16 to
There were insufficient number of events, so a median and confidence interval could not be calculated.
|
SECONDARY outcome
Timeframe: Up to 36 monthsFor each treatment arm, adverse event incidence per group will be summarized by severity (highest grade) for those AEs judged by the Investigator to be probably, possibly, or definitely related to the study treatment and will be summarized by frequency and percentage, with all participants treated in that treatment arm as the denominator unless otherwise specified. In addition, Adverse events with missing severity or relationship to study drug will be classified as severe and treatment-related, respectively.
Outcome measures
| Measure |
Arm A (Apalutamide Monotherapy)
n=13 Participants
Participants receive apalutamide PO QD on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity.
|
Arm B (Apalutamide, SBRT)
n=13 Participants
Participants receive apalutamide orally (PO) once a day (QD) on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Beginning 60 days after first dose of apalutamide, participants also undergo stereotactic body radiation therapy for 1-5 fractions.
|
|---|---|---|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Hot Flashes, Grade 3
|
1 Participants
|
0 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Lymphocyte count decreased, Grade 3
|
0 Participants
|
2 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Neutrophil count decreased, Grade 2
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Pruritus, Grade 2
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Alopecia, Grade 1
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Blurred Vision, Grade 1
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Constipation, Grade 1
|
1 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Depression, Grade 1
|
0 Participants
|
2 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Diarrhea, Grade 2
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Dizziness, Grade 1
|
1 Participants
|
2 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Dysgeusia, Grade 1
|
1 Participants
|
0 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Fatigue, Grade 3
|
1 Participants
|
0 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Hallucinations, Grade 1
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Hypertension, Grade 3
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Hypothyroidism, Grade 2
|
2 Participants
|
0 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Muscle weakness lower limb, Grade 1
|
1 Participants
|
0 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Nausea, Grade 1
|
1 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Neoplasms benign, malignant and unspecified (incl cysts and polyps) - Other, specify, Grade 1
|
1 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
Rash maculo-papular, Grade 3
|
0 Participants
|
1 Participants
|
|
Number of Participants With Treatment-related Adverse Events (AEs)
White blood cell decreased, Grade 2
|
0 Participants
|
2 Participants
|
Adverse Events
Arm A (Apalutamide Monotherapy)
Serious events: 0 serious events
Other events: 13 other events
Deaths: 0 deaths
Arm B (Apalutamide, SBRT)
Serious events: 1 serious events
Other events: 13 other events
Deaths: 1 deaths
Serious adverse events
| Measure |
Arm A (Apalutamide Monotherapy)
n=13 participants at risk
Participants receive apalutamide PO QD on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity.
|
Arm B (Apalutamide, SBRT)
n=13 participants at risk
Participants receive apalutamide orally (PO) once a day (QD) on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Beginning 60 days after first dose of apalutamide, participants also undergo stereotactic body radiation therapy for 1-5 fractions.
|
|---|---|---|
|
Blood and lymphatic system disorders
Hematuria
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
Other adverse events
| Measure |
Arm A (Apalutamide Monotherapy)
n=13 participants at risk
Participants receive apalutamide PO QD on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity.
|
Arm B (Apalutamide, SBRT)
n=13 participants at risk
Participants receive apalutamide orally (PO) once a day (QD) on days 1-28. Courses repeat every 28 days for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Beginning 60 days after first dose of apalutamide, participants also undergo stereotactic body radiation therapy for 1-5 fractions.
|
|---|---|---|
|
Psychiatric disorders
Hallucinations
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Renal and urinary disorders
Hematuria
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Renal and urinary disorders
Urinary urgency
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Respiratory, thoracic and mediastinal disorders
Allergic rhinitis
|
0.00%
0/13 • Up to 36 months
|
15.4%
2/13 • Number of events 3 • Up to 36 months
|
|
Respiratory, thoracic and mediastinal disorders
Cough
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Respiratory, thoracic and mediastinal disorders
Nasal Congestion
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Respiratory, thoracic and mediastinal disorders
Respiratory, thoracic and mediastinal disorders - Other, specify
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Respiratory, thoracic and mediastinal disorders
Sore Throat
|
7.7%
1/13 • Number of events 2 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Skin and subcutaneous tissue disorders
Alopecia
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Skin and subcutaneous tissue disorders
Pruritus
|
0.00%
0/13 • Up to 36 months
|
15.4%
2/13 • Number of events 4 • Up to 36 months
|
|
Skin and subcutaneous tissue disorders
Rash maculo-papular
|
0.00%
0/13 • Up to 36 months
|
23.1%
3/13 • Number of events 7 • Up to 36 months
|
|
Skin and subcutaneous tissue disorders
Skin and subcutaneous tissue disorders - Other, specify
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Vascular disorders
Hot Flashes
|
23.1%
3/13 • Number of events 4 • Up to 36 months
|
15.4%
2/13 • Number of events 2 • Up to 36 months
|
|
Vascular disorders
Hypertension
|
0.00%
0/13 • Up to 36 months
|
23.1%
3/13 • Number of events 4 • Up to 36 months
|
|
Gastrointestinal disorders
Constipation
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
15.4%
2/13 • Number of events 2 • Up to 36 months
|
|
Gastrointestinal disorders
Diarrhea
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
38.5%
5/13 • Number of events 7 • Up to 36 months
|
|
Gastrointestinal disorders
Nausea
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
23.1%
3/13 • Number of events 3 • Up to 36 months
|
|
General disorders
Fatigue
|
61.5%
8/13 • Number of events 11 • Up to 36 months
|
76.9%
10/13 • Number of events 13 • Up to 36 months
|
|
General disorders
Gait disturbance
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
General disorders
Non-cardiac chest pain
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
General disorders
General disorders and administration site conditions - Other, specify
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Infections and infestations
Eye Infection
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Infections and infestations
Upper respiratory infection
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Infections and infestations
Infections and infestations - Other, specify
|
15.4%
2/13 • Number of events 2 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Investigations
Aspartate aminotransferase increased
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Investigations
Lymphocyte count decreased
|
0.00%
0/13 • Up to 36 months
|
23.1%
3/13 • Number of events 11 • Up to 36 months
|
|
Investigations
Neutrophil count decreased
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 2 • Up to 36 months
|
|
Investigations
Weight loss
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Investigations
White blood cell decreased
|
0.00%
0/13 • Up to 36 months
|
15.4%
2/13 • Number of events 5 • Up to 36 months
|
|
Metabolism and nutrition disorders
Hyperglycemia
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Metabolism and nutrition disorders
Hyperkalemia
|
0.00%
0/13 • Up to 36 months
|
15.4%
2/13 • Number of events 3 • Up to 36 months
|
|
Musculoskeletal and connective tissue disorders
Back Pain
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
30.8%
4/13 • Number of events 4 • Up to 36 months
|
|
Musculoskeletal and connective tissue disorders
Bone Pain
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 2 • Up to 36 months
|
|
Musculoskeletal and connective tissue disorders
Flank Pain
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Musculoskeletal and connective tissue disorders
Musculoskeletal and connective tissue disorders - Other, specify
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Musculoskeletal and connective tissue disorders
Chest wall pain
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Musculoskeletal and connective tissue disorders
Muscle weakness lower limb
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Neoplasms benign, malignant and unspecified (incl cysts and polyps) - Other, specify
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Nervous system disorders
Dizziness
|
15.4%
2/13 • Number of events 3 • Up to 36 months
|
15.4%
2/13 • Number of events 3 • Up to 36 months
|
|
Nervous system disorders
Peripheral sensory neuropathy
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Nervous system disorders
Syncope
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Nervous system disorders
Presyncope
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Nervous system disorders
Dysgeusia
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
0.00%
0/13 • Up to 36 months
|
|
Psychiatric disorders
Depression
|
0.00%
0/13 • Up to 36 months
|
15.4%
2/13 • Number of events 2 • Up to 36 months
|
|
Endocrine disorders
Hypothyroidism
|
23.1%
3/13 • Number of events 5 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Eye disorders
Eye Disorders - Other, specify
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Eye disorders
Blurred vision
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 1 • Up to 36 months
|
|
Gastrointestinal disorders
Abdominal Pain
|
0.00%
0/13 • Up to 36 months
|
7.7%
1/13 • Number of events 2 • Up to 36 months
|
Additional Information
Dr. Rahul Aggarwal, MD
University of California, San Francisco
Phone: (415) 476-1000
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place